A post-Fukushima effort to crowdsource radiation data in Japan has since become the largest source of radiation data in the country. And it's now set to expand to other parts of the world. Catherine Winter reports from Tokyo.

A post-Fukushima effort to crowdsource radiation data in Japan has since become the largest source of radiation data in the country. And it's now set to expand to other parts of the world. Catherine Winter reports from Tokyo.

A post-Fukushima effort to crowdsource radiation data in Japan has since become the largest source of radiation data in the country. And it's now set to expand to other parts of the world. Catherine Winter reports from Tokyo.